This project will look at Pan communication skills using discourse and non-verbal communication analysis. Because of our interest in the evolutionary background for human communication/in identifying the foundation that was present before the hominoid-ape split 5-7 million years ago-we plan to utilize both species of Pan-Pan paniscus and Pan troglodytes, basing the themes of our species comparative analyses on prior research concerning the development of cladistic analysis to specific a likely phylogenetic time line for the evolution of different discourse skills. Utilizing longitudinal data on the visual communication (arbitrary visual symbols and gestures) comparative studies on the development of discourse skills in an interactional and communicative context: (1) the development and use of combinations in conversational context; (2) the development and socialization of conversational "repair." (3) a developmental study of informativeness, (4) a developmental study of discourse processes, cohesion and semantic domains; (5) the development of topic as a discourse notion; (6) the role of eye gaze (and other non- verbal mechanisms) in the development of discourse.